Bookcase



FIG. 1 is a left front perspective view of a bookcase showing my newdesign;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a front elevational view thereof; and,

FIG. 4 is a right side elevational view thereof.

The views of the bookcase not shown form no part of the claimed design.The dashed lines represent environmental elements only and form no partof the claimed design.

The ornamental design for a bookcase, as shown and described.